Systems and methods of compression ignition engines

ABSTRACT

Apparatuses, systems and method for utilizing multi-zoned combustion chambers (and/or multiple combustion chambers) for achieving compression ignition (and/or spark-assisted or fuel-assisted compression ignition) in an internal combustion engine are provided. In addition, improved apparatuses, systems and methods for achieving and/or controlling compression ignition (and/or spark-assisted or fuel-assisted compression ignition) in a “Siamese cylinder” internal combustion engine are provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 15/948,089 filed Apr. 9, 2018 and now U.S. Pat. No.10,927,750, which claims priority pursuant to 35 U.S.C. 119(e) to U.S.Provisional Patent Application Ser. No. 62/483,191, filed Apr. 7, 2017,and U.S. Provisional Patent Application Ser. No. 62/490,056, filed Apr.26, 2017, and U.S. Provisional Patent Application Ser. No. 62/500,475,filed May 2, 2017, and U.S. Provisional Patent Application Ser. No.62/554,429, filed Sep. 5, 2017, and U.S. Provisional Patent ApplicationSer. No. 62/627,029, filed Feb. 6, 2018, and is a continuation in partof U.S. patent application Ser. No. 15/400,813 filed Jan. 6, 2017 andnow U.S. Pat. No. 10,125,666, which claims priority pursuant to 35U.S.C. 119(e) to U.S. Provisional Patent Application Ser. No.62/278,919, filed Jan. 14, 2016, and U.S. Provisional Patent ApplicationSer. No. 62/286,795, filed Jan. 25, 2016, and U.S. Provisional PatentApplication Ser. No. 62/295,445, filed Feb. 15, 2016, and U.S.Provisional Patent Application Ser. No. 62/326,594, riled Apr. 22, 2016,and U.S. Provisional Patent Application Ser. No. 62/337,727, filed May17, 2016, and U.S. Provisional Patent Application Ser. No. 62/344,230,filed Jun. 1, 2016, and U.S. Provisional Patent Application Ser. No.62/417,897, filed Nov. 4, 2016, and U.S. Provisional Patent ApplicationSer. No. 62/442,336, filed Jan. 4, 2017, the entire disclosures of whichare incorporated herein by reference.

FIELD OF THE INVENTION

The present inventive concept relates generally to apparatuses, systemsand methods for achieving compression ignition (and/or spark-assisted orfuel-assisted compression ignition) in an internal combustion engine.More particularly, the present inventive concept is concerned withimproved apparatuses, systems and method for utilizing multi-zonedcombustion chambers (and/or multiple combustion chambers) for achievingcompression ignition (and/or spark-assisted or fuel-assisted compressionignition) in an internal combustion engine. In addition, the presentinventive concept is concerned with improved apparatuses, systems andmethods for achieving and/or controlling compression ignition (and/orspark-assisted or fuel-assisted compression ignition) in internalcombustion engines, including “Siamese cylinder” internal combustionengines.

BACKGROUND OF THE INVENTION

Virtually since the invention of the internal combustion engine, peoplehave been trying to increase efficiency and lower emissions. Two commoncategories of internal combustion engines are spark ignition andcompression ignition (as used herein, the phrase “compression ignition”includes, but is not necessarily limited to: Diesel/Stratified ChargeCompression Ignition (SCCI), Homogeneous Charge Compression Ignition(HCCI), Homogenous Compression Ignition (HCI), Homogeneous Charge withSpark Ignition (HCSI), Gas Direct Compression Ignition (GDCI), dieseland other fuels, as well as fuel blends, carbureted and/or injected asdifferent types of fuel and fuel blend compression ignition,spark-assisted ignition, fuel-assisted ignition, etc.).

Spark ignition engines utilize a spark from a spark plug to ignite thecombustion process of the air-fuel mixture within the combustion chamberof the engine. In contrast, compression ignition engines utilizetemperature and density increases in the air-fuel mixture within thecombustion chamber to auto-ignite the combustion process. Spark ignitionengines typically have much lower efficiency than compression ignitionengines. Because the flame propagates from the point of ignition (i.e.the spark), it results in incomplete combustion. In compression ignitionengines, no flame front exists, instead because the combustion isinitiated by increased pressure, the ignition is uniformed, and/or takesplace, within multiple places within the combustion chamber, causingnearly simultaneous/instant ignition throughout the entire air-fuelmixture and resulting in more complete combustion. Conventionalcompression ignition engines must be carefully designed to provide forcombustion just before top dead center, taking into account the timingof the fuel injected (typically, direct injected to control combustioncycle) into the combustion chamber, to avoid catastrophic damage to theengine if combustion occurs too early.

Due to the nearly instantaneous ignition of the entire air-fuel mixturewithin the combustion chamber of a compression ignition engine, anenormous amount of pressure is created within the combustion chamber allat once, as opposed to the more gradual increase in pressure that wouldbe created as the flame propagates through the combustion chamber of aspark ignition engine. This immediate pressure increase is particularlyhigh in homogeneous charge compression ignition (HCCI) engines. As such,engine manufacturers have been required to carefully control compressionignition engines such that the ignition occurs when the piston of theengine is at top dead center or moving down from top dead center.Otherwise, if the ignition occurs before the piston reaches top deadcenter, catastrophic engine failure will result (i.e. including, but notlimited to, bent piston rods, collapsed piston skirts, blown headgaskets, etc.). Nevertheless, such precise control requirementsnecessitate extremely tight design parameters, limiting compressionratio and/or operating temperature for such engines. Too high acompression ratio can result in auto-ignition before top dead center.Reducing compression ratio, however, increases the temperature requiredto achieve auto-ignition, thus making the engine difficult to run incold temperature environments.

U.S. Pat. No. 6,557,520 to Roberts, Jr., the entire disclosure of whichis incorporated herein by reference, discloses a multi-zoned combustionchamber and method for combustion control in compression ignitionengines that helps to control the immediate combustion pressure surgecreated in a compression ignition engine. Roberts, Jr. physicallysegregates the combustion chamber into multiple smaller, sealed,chambers (e.g. a primary chamber and at least a secondary chamber, aswell as possibly a tertiary, or more subsequent chambers) through astepped shaped design of the piston and cylinder head. Specifically,referring to FIG. 1 , Roberts, Jr. discloses a cup-shaped piston 140that has a central recess 141 surrounded by a circumferential protrudingwall 142 portion of the piston. The cylinder head 132 of Roberts, Jr. isconfigured to matingly receive the cup-shape of the piston and has acentral protuberance 133 surrounded by a circumferential recess 134. Thecentral recess 141 of the piston is adapted to slidingly receive thecentral protuberance 133 of the head, and the circumferentiallyprotruding wall 142 is adapted to be slidingly received between thepiston cylinder 130 and the central protuberance 133 and the recess 134.FIGS. 2-8 illustrate the multiphase sequence of the internal combustionprocesses of the engine of Roberts, Jr., in which combustion isinitiated in the primary chamber 143 while delaying combustion in thesecondary chamber 144.

FIG. 2 illustrates a first phase, which begins after a normal inductionstroke, in which air is introduced into the combustion chamber 146. Fuelis delivered and mixed into the combustion system through valve 41and/or fuel injector 62.

FIG. 3 illustrates a later, second phase in the compression stroke ofthe combustion chamber 146. This phase illustrates the initiation ofchemical reactions within the unburned fuel/air masses 150, 151 in theprimary chamber 143 and the secondary chamber 144 due to compressionheating. At this phase, the combustion chamber 146 is separated into twoindividual combustion chambers (the primary chamber 143 and thesecondary chamber 144) due to the design and motion of the piston andthe design of the combustion chamber.

FIG. 4 illustrates a third phase where the fuel/air mass 150 trappedwithin the primary chamber 143 undergoes a compression ignition process.When compression ignition is undertaken, rapid combustion of thefuel/air mass 150 in the primary chamber 143 occurs. The size of theprimary chamber 143 modulates the amount of energy trapped in theprimary chamber 143 so that when the fuel/air mass 150 ignites, thepressure and temperature that is achieved can be controlled throughdesign. The pressure required to ignite the fuel/air mass 150 is afunction of thermodynamic interaction. The primary chamber 143 and thesecondary chamber 144 have different compression and/or pressure ratiovalues, so that the fuel/air mass 151 within the secondary chamber 144will not auto-ignite due to compression from the piston.

FIG. 5 illustrates a fourth phase where the compression ignition processproceeds to a rapid combustion process within the primary chamber 143.Since the primary chamber 143 is being utilized as an ignition controlfor the secondary chamber 144, the timing after TDC is not necessary.

FIG. 6 illustrates a fifth phase where the fuel/air mass 150 has beenconverted to a high pressure, high temperature, combusting gas 150Awithin the primary chamber 143. In Roberts, Jr., the fifth phase occursafter TDC, when the piston 140 is moving in the direction of a downstroke 44. In this fifth phase, the combusting gas 150A continues toexpand and remains segregated from the remaining fuel/air mass 151 (orremaining combustible gas) in the secondary chamber 144.

FIG. 7 illustrates a sixth phase where the piston 140 has moved to apredetermined position where segregation of the primary chamber 143 andsecondary chamber 144 is eliminated. The sixth phase occurs after TDC,as the piston continues to move in the direction of a down stroke 44. Inthis phase, combustion of the remaining fuel/air mass 151 in thesecondary chamber 144 is initiated. FIG. 7 shows the combusting gas 150Afrom the primary chamber 143 thermodynamically communicating with theremaining fuel/air mass 151 of the secondary chamber 144 and causing itto be converted into a remaining combusting gas 151A. After the primarychamber 143 and secondary chamber 144 have been desegregated and thecombusting gas 150A of the primary chamber 143 is allowed to communicatewith the secondary chamber 144, the combusting gas 150A in the primarychamber 143 and the thermodynamic state of the primary chamber 143 isused as the ignition source for the remaining fuel/air mass 151 in thesecondary chamber 144.

FIG. 8 illustrates a seventh phase where all of the remaining fuel/airmass 151 of the secondary chamber 144 has been ignited and convertedinto a combusting gas 151A. Ignition of the secondary chamber can be bycompression ignition, direct flame contact, or a combination thereof.

The multi-phase combustion process of Roberts, Jr. allows the combustionprocess to be initiated by compression caused by the piston, withoutrequiring precise control of the reaction to ensure it occurs when thepiston is at or past top dead center. Instead, the segregation of thecombustion chamber allows the piston to cause auto-ignition only in theprimary chamber, which has a higher compression ratio and/or pressureratio than the secondary chamber. The relatively small volume of theprimary combustion chamber reduces the downward force on the piston,reducing the risk of damage to the engine even if the piston is in itsupstroke. The remaining combustion does not occur until the piston is inits down stroke and the seal/barrier (created by the piston and headshape) between the primary and secondary combustion chamber is removed.

Despite the benefits provided by the multi-phase combustion process, theapparatus and method of Roberts Jr. suffer from several drawbacks. Forexample, the design of the piston central recess 141, andcircumferential recess 134 of the head, create trap volume areas inwhich it is difficult to obtain a homogeneous air-fuel mixture (as usedhereafter meaning exhaust, Exhaust Gas Recirculation (EGR), intake airand fuel are all mixed in a homogeneous fashion). This can significantlyreduce the performance and efficiency of the engine. In addition, thecentral recess 141 of the piston lowers the position of the wrist-pinconnecting the piston to the rod. Such a design increases likelihood ofengine failure due to decreased control of piston cradle rock/pistonslap as well as reduced strength at an area of significant stress on thepiston. Moreover, the physical seals that are created between theprimary and secondary (tertiary, on so on) combustion chambers, compoundthe difficulty in creating a homogenous air-fuel mixture, making itdifficult to control engine knock. Therefore, it would be beneficial toprovide systems and methods for achieving multi-phase compressionignition that reduce trap volume, reducing engine knock, and/or decreaselikelihood of engine failure, to have control over compression ignitionat a multitude of ranges of RPM's, temperatures and/or multiple loads(with and without boost—e.g. supercharge, turbo, etc.).

In addition, the use of compression ignition in “Siamese cylinder”engines has been difficult or impossible to control. “Siamese cylinder”engines are multi-cylinder engines in which the engine cylinders arearranged in such a way that they do not have channels in the cylinderwalls between adjacent cylinders for water or other coolant tocirculate. Such arrangements are typically used when it is desirable tohave an engine block of limited size or when the stability of thecylinder bores is of concern (such as in racing engines). The lack ofcoolant results in hot spots at the locations in which adjacentcylinders intersect with one another, which makes control of compressionignition difficult. Therefore, it would be beneficial to provideapparatuses, systems and methods for achieving and/or controllingcompression ignition (including spark-assisted and/or fuel-assistedcompression ignition) in a “Siamese cylinder” internal combustionengine.

SUMMARY OF THE INVENTION

The present inventive concept comprises apparatuses, systems and methodsfor achieving multi-phase compression ignition in a manner similar tothat described in Roberts, Jr., while alsoreducing/minimizing/eliminating trap volume, reducing carbon buildup,reducing engine knock, and/or decreasing likelihood of engine failurethat is inherent in Roberts, Jr.'s designs, and providing control overcompression ignition at a multitude of ranges of RPM's, temperaturesand/or multiple loads (with and without boosting of intake charge of anykind). The inventive concept includes a stepped piston that includes agenerally central protuberance (or multiple protuberances) that mateswith a central recess (or recesses) in the cylinder head to physicallysegregate the combustion chamber of the engine into multiple smallerchambers (e.g. a primary chamber and at least a secondary chamber, aswell as possibly a tertiary, or more subsequent chambers). In someembodiments, although the stepped piston physically segregates thecombustion chamber into multiple chambers, the separate chambers are notphysically sealed off from one another, allowing fluid communicationthere between. In some such embodiments, the fluid communication betweencombustion chambers is controlled through a multiphasic dynamiccompression ignition combustion process in which there is constant fluidcommunication between the primary and secondary (as well as tertiary andso forth) combustion chambers/ignition sources. In such embodiments, themultiphasic dynamic process aids in creating a homogenous air-fuelmixture and slows down ignition to allow the piston to move past topdead center before full ignition occurs (e.g. throughout the entirecombustion chamber including primary, secondary, etc.).

It will be appreciated that various embodiments of the instant inventiveconcept will be utilized in connection with any type of compressionignition engine technology now known or hereafter discovered, including,but not limited to, Diesel/Stratified Charge Compression Ignition,Homogeneous Charge Compression Ignition, Homogenous Compression Ignition(HCI), Homogeneous Charge with Spark Ignition, Gas Direct CompressionIgnition, diesel and other fuels, as well as fuel blends (includingliquid fuels, solid fuels, natural fuels, or other fuels now known orhereafter developed or discovered), carbureted and/or injected asdifferent types of fuel and fuel blend compression ignition,spark-assisted ignition, fuel-assisted ignition, and the like. In someembodiments fuel is introduced (e.g. direct injection, or other form offuel intake) separately into different parts of the combustion chamber,such as separately into primary and secondary chambers. In some suchembodiments, different types of fuel are introduced into one or moreseparate parts of the combustion chamber (e.g. diesel fuel in primaryand gas in secondary, etc.). Embodiments of the instant inventiveconcept include both two cycle and four cycle technologies, Millercycle, Atkinson cycle, rotary engine, modified piston engines (e.g.offset elliptical pistons or other convoluted shapes of pistons),turbine fans, opposed piston, Scuderi or other split cycle engines, andother engine technologies now known or hereinafter developed. In sometwo cycle embodiments, intake and exhaust valves are included in thehead. In other embodiments, the exhaust is located on the side and thepiston acts as the exhaust valve to control exhaust. In some preferredembodiments, at least one intake valve is located in the head to helpminimize trap volume. In some embodiments, a butterfly (or othersuitable valve assembly) is included within the exhaust. In suchembodiments, the valve is utilized to trap heat and/or exhaust gasinside the combustion chamber to suffocate (or partially suffocate) thenext combustion cycle and assist with compression ignition in theengine. In some such embodiments, the trapped heat functions as acatalyst for the next combustion cycle. It will be appreciated that invarious embodiments the butterfly exhaust valve will be opened or closedor adjusted at any given time to control the compression ignitionprocess. In some embodiments, the butterfly valve is opened further athigher RPM's and closed more at lower RPM's. It will be appreciated thatthe butterfly exhaust valve of the inventive concept will be utilizedwith any of the engine embodiments herein (such as the multiphasicdynamic compression ignition combustion engines disclosed herein), aloneor in combination with other features, as well as in connection withother two cycle, four cycle or other engine types of the prior art andhereinafter discovered (such as engines that do not utilize multiphasicdynamic compression ignition combustion).

Although not shown, various embodiments of the inventive concept includefuel injectors located at various locations about the combustion chamberto provide the desired homogenous air/fuel/EGR mixture throughout thechamber. In some embodiments injectors are located at varying angles andorientations, including at varying crank angles and/or at multipledifferent crank angles within a single cycle, to provide desiredmixtures of fuel/air into the combustion chamber. In some embodiments,no fuel is injected directly into the combustion chamber, instead thefuel is mixed into the air in a pre-intake area (e.g. prior to enteringthe combustion chamber through the intake valve(s)). In variousembodiments, the air-fuel mixture is accomplished via high or lowpressure port, throttle body (including upstream linear EGR connectedinto throttle body, and/or downstream fuel injection to assist in betteratomization of air/fuel and/or EGR blending), sequential, assisted port,direct or indirect injections, or any combination thereof. In stillother embodiments, carburetor(s) is/are used to accomplish the air-fuelmixture, or a portion thereof. In some embodiments, a stratified cloudinjection for throttle body is utilized, in which a fuel pressure of 90PSI or higher is created through electric or mechanical pumps to createa fine mist with high atomization capability. In other low pressureinjection embodiments, a fuel pressure of 10 PSI or higher is utilized.Some embodiments include single, twin, triple, quads, etc. throttle highpressure cloud throttle body. The high pressure atomizes the fuel toresult in improved homogenous fuel-mix for HCCI. In some embodiments,the inventive concept utilizes high pressure fuel injection via amultitude of nozzles to create the cloud injection.

In some embodiments standard throttle control is utilized to control theintake gases of the engine. In some embodiments, a butterfly throttlecontrol is utilized to restrict intake gases. In some embodimentsthrottle body with a butterfly assembly and/or carburetor withadjustable lean/rich control function to control the amount of air/fuelentering the engine intake is utilized. In some embodiments, anelectronic control is utilized in connection with the enrichment needleto control the lean/rich function and control the amount of fuel in theintake at any given time. In some embodiments, the electronic control ofthe lean/rich function is part of a carburetor. In some embodiments, acarburetor includes throttle control of intake gases.

In some embodiments, spark plugs or glow plugs are utilized to aid inignition. For example, in some embodiments, spark plugs are utilized inlow temperature, low RPM or engine startup situations. The angle andlocation of the spark plug(s) varies based on desired performance of theengine. In some embodiments, the spark plug(s) is positioned at a 45degree angle to the piston to prevent interference with intake valves.In some embodiments, spark plugs are located in the primary chamber. Insome embodiments, spark plugs are located in the secondary chamber(tertiary, etc.). In some embodiments, spark plugs are located in bothprimary and secondary chambers. In various embodiments of the presetinvention, one or more spark plug or glow plug extends through a wall ofthe head into one or more chamber. In some embodiments, one or morespark plug and glow plug extends into a single compression chamber.

Some embodiments of the present inventive concept comprise apparatuses,systems and methods for achieving multi-phase compression ignition in a“Siamese cylinder” internal combustion engine in a manner similar tothat described above. In some embodiments, the inventive conceptincludes a stepped piston that includes a generally central protuberancethat mates with a central recess in the cylinder head to physicallysegregate the combustion chamber of the engine into multiple smallerchambers (e.g. a primary chamber and at least a secondary chamber, aswell as possibly a tertiary, or more subsequent chambers). In someembodiments, although the stepped piston physically segregates thecombustion chamber into multiple chambers, the separate chambers are notphysically sealed off from one another, allowing fluid communicationthere between. In some such embodiments, the fluid communication betweencombustion chambers is controlled through a multiphasic dynamiccompression ignition combustion process in which there is constant fluidcommunication between the primary and secondary (as well as tertiary andso forth) combustion chambers/ignition sources. In such embodiments, themultiphasic dynamic process aids in creating a homogenous air-fuelmixture and slows down ignition to allow the piston to move past topdead center before full ignition occurs (e.g. throughout the entirecombustion chamber including primary, secondary, etc.).

The foregoing and other objects are intended to be illustrative of theinventive concept and are not meant in a limiting sense. Many possibleembodiments of the inventive concept may be made and will be readilyevident upon a study of the following specification and accompanyingdrawings comprising a part thereof. Various features and subcombinationsof inventive concept may be employed without reference to other featuresand subcombinations. Other objects and advantages of this inventiveconcept will become apparent from the following description taken inconnection with the accompanying drawings, wherein is set forth by wayof illustration and example, an embodiment of this inventive concept andvarious features thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the inventive concept, illustrative of thebest mode in which the applicant has contemplated applying theprinciples, is set forth in the following description and is shown inthe drawings.

FIG. 1 shows a cross-sectional view of a multi-zone combustion chambercompression ignition engine of the prior art.

FIGS. 2-8 illustrate the multiple phases of combustion in the prior artengine of FIG. 1 .

FIG. 9 shows a cross-sectional view of a multi-zone combustion chambercompression ignition engine of an embodiment of the instant inventiveconcept. In FIG. 9 , the piston is positioned such that the combustionchamber is not segregated. In other words, the primary and secondary(and any subsequent) combustion chambers are all in complete fluidcommunication with each other.

FIG. 10 shows a cross-sectional view of the engine of FIG. 9 , with thepiston positioned such that the combustion chamber is segregated into aprimary combustion chamber and a secondary combustion chamber.

FIG. 11 is a top cross-sectional plan view of the piston of FIGS. 9 and10 taken along section line 11-11 of FIG. 9 .

FIG. 12 is a bottom cross-sectional plan view of the head of FIGS. 9 and10 taken along section line 12-12 of FIG. 9 .

FIG. 13 shows a cross-sectional view of a multi-zone combustion chambercompression ignition engine of another embodiment of the instantinventive concept. In FIG. 13 , the piston is positioned such that thecombustion chamber is not segregated. In other words, the primary andsecondary (and any subsequent) combustion chambers are all in completefluid communication with each other. Furthermore, in FIG. 13 , ports areincluded in the piston to provide for multiphasic dynamic compressionignition combustion. In addition, ports are included in the head to aidin creating a homogenous air-fuel mixture by creating spin within thecombustion chamber(s) before, after and/or at auto-ignition.

FIG. 14 shows a cross-sectional view of the engine of FIG. 13 , with thepiston positioned such that the combustion chamber is segregated into aprimary combustion chamber and a secondary combustion chamber. As isshown in FIG. 14 , even when the combustion chambers are segregated,they are not sealed off from each other.

FIG. 15 is a top cross-sectional plan view of the piston of FIGS. 13 and14 taken along section line 19-19 of FIG. 13 .

FIG. 16 is a bottom cross-sectional plan view of the head of FIGS. 13and 14 taken along section line 18-18 of FIG. 13 .

FIG. 17 shows a cross-sectional view of an alternate embodiment of theengine of FIGS. 9 and 10 , with the piston positioned such that thecombustion chamber is segregated into a primary combustion chamber and asecondary combustion chamber.

FIGS. 18A, 18B, and 18C show representative cross-sectional plan viewsof a multi-staged injector of an embodiment of the inventive concept.

FIG. 19A shows embodiment of two cycle engine of the inventive conceptin which the piston functions as the exhaust and intake valves, andfurther including a butterfly valve within the exhaust outlet to trapheat and exhaust gas inside the combustion chamber to aid in compressionignition. FIGS. 19B and 19C show other embodiments of engines of theinventive concept that include a butterfly valve within an exhaustoutlet to trap heat and exhaust gas inside the combustion chamber to aidin compression ignition.

FIG. 20 shows a representative top plan view of a three cylinder Siamesecylinder engine, depicting the cylinder and valve arrangement of anembodiment of the inventive concept.

FIG. 21 shows a front cross-section elevation view of the engine of FIG.20 .

FIG. 22 shows a representative top plan view of another embodiment of athree cylinder Siamese cylinder engine that includes multipleprotuberances of the inventive concept.

FIG. 23 shows a cross-sectional view of a multi-zone combustion chambercompression ignition engine of a flathead (or side-valve) engine styleembodiment of the instant inventive concept.

FIG. 24 shows a cross sectional view of the engine block of the engineof FIG. 23 taken along section line 24-24 of FIG. 23 .

FIG. 25 shows a cross sectional view of the cylinder head of the engineof FIG. 23 taken along section line 25-25 of FIG. 23 .

FIG. 26 shows a top view of an embodiment of engine block having sixside valves positioned along an arc on either side of a piston.

FIG. 27 is a bottom view of a head associated with the engine block ofFIG. 26 , the head defining a recess creating a corridor connecting thevalves to the combustion chamber of the engine block.

FIG. 28 shows a top view of an embodiment of engine block having threeside valves positioned along an arc on one side of a piston.

FIG. 29 is a bottom view of a head associated with the engine block ofFIG. 28 , the head defining a recess creating a corridor connecting thevalves to the combustion chamber of the engine block.

FIG. 30 is a top view of an embodiment of an engine block similar to theembodiment of FIG. 26 with each set of valves being positioned along astraight line along either side of the piston.

FIG. 31 is a top view of an embodiment of an engine block similar to theembodiment of FIG. 28 with the valves being positioned along a straightline along one side of the piston.

FIG. 32 shows a top view of an embodiment of engine block having firstand second pistons positioned adjacent to each other.

FIG. 33 is a bottom view of a head associated with the engine block ofFIGS. 32 and 34 , the head defining a recess associated with eachpiston, each recess creating a corridor connecting each set of valveswith a respective combustion chamber of the engine block.

FIG. 34 is a top view of an embodiment of an engine block similar to theembodiment of FIG. 32 with each set of valves being positioned along astraight line along respective sides of respective pistons.

FIG. 35 is a bottom view of a head associated with the engine block ofFIGS. 32 and 34 , the head defining a recess associated with each pistonfor creating a corridor connecting each set of valves with a respectivecombustion chamber of the engine block and a recess connecting thecombustion chambers to each other.

FIG. 36 shows a top view of an embodiment of engine block having firstand second pistons.

FIG. 37 is a bottom view of a head associated with the engine block ofFIGS. 36, 38, 39, and 40 , the head defining first and second recesscreating first and second corridors connecting respective first andsecond sets of valves with respective first and second combustionchambers of the engine block and a third recess connecting the third setof valves to each of the first and second combustion chambers. It willbe appreciated that other embodiments include different recessconfigurations.

FIG. 38 is a top view of an embodiment of an engine block similar to theembodiment of FIG. 36 with two of the valves of the third set of valvesbeing positioned along a first are associated with the first piston andtwo of the valves being positioned along a second arc associated withthe second piston, the center valve being positioned at an intersectionpoint of each of the first and second arcs.

FIG. 39 is a top view of an embodiment of an engine block similar to theembodiment of FIG. 36 with two of the valves of the third set of valvesbeing positioned along a second arc associated with the second pistonand two of the valves being positioned along a first arc associated withthe first piston, the center valve being positioned at an intersectionpoint of each of the first and second arcs.

FIG. 40 is a top view of an embodiment of an engine block similar to theembodiment of FIG. 40 with the center valve of the third set of valvesbeing removed.

FIG. 41 is a bottom view of a head associated with the engine block ofFIG. 40 , the head defining first and second recesses creatingrespective first and second corridors connecting respective first andsecond sets of valves with a respective combustion chamber of the engineblock. The head further defines a third recess connecting the firstcombustion chamber with a first valve of the third set of valves and afourth recess connecting the second combustion chamber with a secondvalve of the third set of valves.

FIG. 42 shows a top view of an embodiment of engine block having twoside valves positioned inline with the engine crank.

FIG. 43 is a bottom view of a head associated with the engine block ofFIG. 42 , the head defining a recess creating a corridor connecting thevalves to the combustion chamber of the engine block.

FIG. 44 shows a top view of an embodiment of engine block having twoside valves positioned inline with the engine crank

FIG. 45 is a bottom view of a head associated with the engine block ofFIG. 44 , the head defining a recess creating a corridor connecting thevalves to the combustion chamber of the engine block.

FIG. 46 shows a top view of an embodiment of engine block having twoside valves positioned inline with the engine crank

FIG. 47 is a bottom view of a head associated with the engine block ofFIG. 46 , the head defining a recess creating a corridor connecting thevalves to the combustion chamber of the engine block.

FIG. 48 shows a top view of an embodiment of engine block having twoside valves positioned inline with the engine crank

FIG. 49 is a bottom view of a head associated with the engine block ofFIG. 48 , the head defining a recess creating a corridor connecting thevalves to the combustion chamber of the engine block.

FIG. 50 shows a top view of an embodiment of engine block having fourside valves positioned inline with the engine crank, two on each side ofthe cylinder.

FIG. 51 is a bottom view of a head associated with the engine block ofFIG. 50 , the head defining a recess creating a corridor connecting thevalves to the combustion chamber of the engine block.

FIG. 52 shows a top view of an embodiment of engine block having fourside valves positioned inline with the engine crank, two on each side ofthe cylinder.

FIG. 53 is a bottom view of a head associated with the engine block ofFIG. 52 , the head defining a recess creating a corridor connecting thevalves to the combustion chamber of the engine block.

FIG. 54 shows a top view of an embodiment of engine block having fourside valves positioned inline with the engine crank, two on each side ofthe cylinder.

FIG. 55 is a bottom view of a head associated with the engine block ofFIG. 54 , the head defining a recess creating a corridor connecting thevalves to the combustion chamber of the engine block.

FIG. 56 shows a top view of an embodiment of engine block having fourside valves positioned inline with the engine crank, two on each side ofthe cylinder.

FIG. 57 is a bottom view of a head associated with the engine block ofFIG. 56 , the head defining a recess creating a corridor connecting thevalves to the combustion chamber of the engine block.

FIG. 58 shows a cross-sectional view of a representation of an engine ofthe present invention, a piston of the engine shown at top dead centerand a variable compression ratio piston of the engine shown in a firstlocation;

FIG. 59 shows a cross-sectional view of FIG. 58 with the variablecompression ration piston shown in an intermediate location.

FIG. 60 shows a cross-sectional view of FIG. 58 with the variablecompression ration piston shown in a second location.

FIG. 61 shows a cross-sectional view of FIG. 58 with the piston showndisplaced from top dead center.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

As required, detailed embodiments of the present inventive concept aredisclosed herein; however, it is to be understood that the disclosedembodiments are merely exemplary of the principles of the inventiveconcept, which may be embodied in various forms. Therefore, specificstructural and functional details disclosed herein are not to beinterpreted as limiting, but merely as a basis for the claims and as arepresentative basis for teaching one skilled in the art to variouslyemploy the present inventive concept in virtually any appropriatelydetailed structure.

Referring to FIGS. 9 through 12 , an exemplary embodiment of theinventive concept includes a piston 100 that is configured toreciprocate axially within a bore of a cylinder 300 such that the pistonis moveable between a top position and a bottom position. A head 500 iscoupled to a top of the cylinder such that a top surface of the pistonis in close proximity to a bottom surface of the head when the piston isin the top position. In some embodiments, the bottom surface of the headand the top surface of the piston are configured to define a specificvolume of one or more voids positioned between the piston and the headwhen the piston is in the top position.

In some embodiments, a generally central protuberance 110 extends fromthe top of the main body of the piston such that the top surface of thepiston is defined partially by a top surface of the main body of thepiston and partially by a top surface of the protuberance. In some suchembodiments, the cylinder head 500 includes a generally central recess510 that is configured to matingly receive the protuberance 110 of thepiston when the protuberance is in an engaged configuration. The centralprotuberance 110 of the piston is adapted to be slidingly received inthe central recess 510 of the head as it moves between an initialengagement configuration and a full engagement configuration, the fullengagement configuration of the protuberance coinciding with the topposition of the piston. As the piston moves from the bottom positiontoward the top position, often referred to as top dead center, thecentral protuberance 110 of the piston moves from a disengagedconfiguration to the initial engaged configuration, which coincides withthe protuberance of the piston being first received by the recess of thehead. As the piston continues to move towards the top position, theprotuberance slides into the central recess 510 of the head, creating aprimary combustion chamber 600 and a secondary combustion chamber 700.The primary combustion chamber 600 is defined by the void between a topsurface of the protuberance and a top surface of the recess. Thesecondary combustion chamber 700 is defined by one or more void betweena top surface of the main body of the piston and a bottom surface of thehead.

In some embodiments, the respective volumes of primary combustionchamber 600 and secondary combustion chamber 700 are designed such thatthe compression ratio and/or pressure ratio of primary combustionchamber 600 is higher than that of secondary combustion chamber 700 (inother embodiments, the reverse is true). In that manner, auto-ignitionof a fuel-air mixture can be obtained in the primary combustion chamber600 either before, at, or after the piston reaches top dead center,without resulting in auto-ignition within the secondary combustionchamber 700. As the piston moves away from the top position, theprotuberance 110 moves from the engaged configuration towards thedisengaged configuration in which the protuberance is displaced from therecess 510 of the head, allowing the pressure created by the combustionwithin the primary combustion chamber 600 to expand into the secondarycombustion chamber 700, initiating combustion, combustion ignitionand/or ignition within the secondary combustion chamber 700.

Referring to FIG. 10 , some embodiments define a gap 800 between anouter circumference of the protuberance 110 and an inner wall of therecess 510 when the protuberance is in the engaged configuration. Insome such embodiments, one or more gap-filling mechanism, such as rings,is coupled to the protuberance 110 and/or secured within the recess 510so as to prevent or otherwise inhibit fluid from flowing from throughthe gap 800. In some such embodiments, the gap filling mechanism createsan air-tight seal between the primary combustion chamber 600 and thesecondary combustion chamber 700 when the protuberance is in the engagedconfiguration. In other embodiments, however, gap filling mechanisms,such as rings (or another seal), are not utilized, as the size of gap800 is designed to allow sufficient pressure to be created withinprimary combustion chamber 600 to create auto-ignition, withoutpermitting sufficient pressure to escape through gap 800 to createignition within secondary combustion chamber 700 while the piston is atthe top position, prior to the piston being in its down stroke. Instillsome embodiments, as discussed below, the primary and secondarycombustion chambers remain in constant fluidic communication with oneanother for the purposes of creating multiphasic dynamic compressionignition combustion. In some embodiments, gap 800 is sufficient toprovide such constant fluidic communication between the primary andsecondary combustion chambers at all times during the piston stroke.

As is shown in FIGS. 9 and 10 , intake valve 400 is located withinrecess 510 of the cylinder head to reduce and/or eliminate trap volume(and/or rich air pockets, and/or unbalanced combustion between theprimary and secondary chambers) within the combustion chamber, and toensure a homogenous air/fuel/EGR mix within the entire combustionchamber (primary and secondary chambers). It will be appreciated that inother embodiments, additional intake valves are included at otherlocations in which trap volume would otherwise exist and/or in whichair/fuel/EGR mix is desired (such as in the secondary combustionchamber). For example in embodiments with tertiary or more combustionchambers, intake valves are included in each combustion chamber. It willfurther be appreciated that in some embodiments the intake valve 400(and/or other intake valves) are opened during at least a portion of theexhaust stroke (and/or in some embodiments, during at least a portion ofthe power and/or compression strokes), to eliminate trap volume. In somesuch embodiments the valve is opened at the top of the exhaust stroke.In some embodiments, exhaust valves, not shown, are located within thesecondary combustion chamber. Still in further embodiments, exhaustvalves (not shown) are included in the recess 510 to help eliminate trapvolume, and/or at other desired locations within the combustion chamber.It will be appreciated that by eliminating trap volume, the inventiveconcept helps to create equal air/fuel and exhaust EGR, hydrocarbons,carbon monoxide and maintain low NOx emissions. The inventive conceptallows for 2 cycle scavenging that is not present in the prior art suchas Roberts Jr. discussed above.

Referring to FIGS. 9 and 10 , the design of the piston 100, with theprotuberance 110 located at the center of piston 100, allows a wrist-pin210 to attach a rod 200 to the piston at a location of increasedthickness of the piston (due to the protuberance). This increasesstrength at a location that otherwise is under increased stress. Inaddition, the relatively high connection on the piston allows forgreater control of the piston and decreased piston slap as the pistonmoves up and down within the cylinder.

Referring to FIGS. 13 through 16 , some embodiments include one or morehead port 520 defined by and extending through a portion of the head500. In some such embodiments, each head port 520 extends between theprimary 600 and secondary 700 combustion chambers when the protuberanceis in the initial engagement configuration. In some embodiments, theports are designed to create a circulatory or spinning, and/or rolland/or tumble, airflow into the combustion chamber(s) as the piston 100reciprocates within the cylinder to create a constant mixture ofair/fuel. This helps to eliminate or otherwise minimize trap volumewithin the combustion chamber. In some embodiments, as is shown in FIGS.13 through 16 , the protuberance 110 operates as a valve to close thehead ports when the protuberance is in the fully engaged configuration.In some such embodiments, the head ports reopen as the protuberancemoves away from the fully engaged configuration. In other embodiments,openings of the head ports are positioned within the recess such thatprimary chamber 600 remains in continuous fluidic communication with thesecondary chamber 700 through at least some of the head ports 520regardless of the position of the protuberance. In some embodiments, asshown in FIGS. 13 through 16 , ports 520 are shown at roughly 45 degreeangles from top to bottom. It will be appreciated that other angles,sizes, shapes, lengths, etc. of ports 520 will be utilized in variousembodiments to create the desired circulation within/between thecombustion chambers. Moreover, the number and positions of the ports520, and exit/entrance angles will vary between embodiments to obtainthe desired circulation. In some embodiments, gap 800 is sufficient toprovide for constant fluidic communication between the primary chamber600 and secondary chamber 700 at all times during the piston stroke.

In some embodiments, as shown in FIGS. 13 through 16 , the protuberancedefines one or more ports 130 extending from a top surface of theprotuberance to a side surface of the protuberance. In some suchembodiments, a single central port 120 extends axially into theprotuberance from a center of the top surface of the protuberance and aplurality of lateral ports extend from the central port to a sidesurface of the protuberance. In some such embodiments, each lateral portextends at an angle relative to the central port such that the length ofany pathway through the central port and any one of the lateral ports isthe substantially the same distance as the length of a pathway throughthe central port and any one of the other lateral ports.

In some embodiments, as shown in FIG. 14 , an opening for at least someof the lateral ports is positioned along the outer surface of theprotuberance such that the lateral port is in fluid communication withthe secondary combustion chamber 700 when the protuberance is in anengaged configuration, regardless of whether the protuberance is in theinitial engaged configuration or the fully engaged configuration. Inthis manner, it is possible to maintain constant and continuous fluidiccommunication between the primary 600 and secondary 700 combustionchambers, aiding in multiphasic dynamic compression ignition combustion.In some embodiments, the ports are designed to create a circulatory orspinning airflow into the combustion chamber(s) as the piston 100reciprocates within the cylinder. This helps to eliminate or otherwiseminimize trap volume within the combustion chamber. In some embodiments,as shown in FIGS. 13 through 16 , ports 120, 130 are shown at variousangles from top to bottom and around the protuberance 110. It will beappreciated that other angles, sizes, shapes, lengths, etc. of ports120, 130 will be utilized in various embodiments to create the desiredcirculation within/between the combustion chambers. Moreover, the numberand positions of the ports 120 and 130, and exit/entrance angles willvary between embodiments to obtain the desired circulation. In someembodiments, as shown in FIG. 15 , ports 130 come off port 120 generallytangentially, so as to help create a circulatory flow within thecombustion chamber.

Referring to FIG. 17 a cross-sectional view of an alternate embodimentof the engine of FIGS. 9 and 10 is shown with the piston positioned suchthat the combustion chamber is segregated into a primary combustionchamber and a secondary combustion chamber. In the embodiment shown inFIG. 17 , the protuberance 110 of the piston 100 includes a groove 115around the circumference of protuberance 110. It will be appreciatedthat similar grooves and/or indentations are included in variousembodiments of the invention similar to those discussed herein,including but not limited to the various embodiments shown with respectto FIGS. 1 through 16 above. In some embodiments multiplegroves/indentations are utilized. The grooves/indentations createfriction to help created a velocity vortex/turbulence within thecombustion chamber(s).

In some embodiments, initial ignition occurs in the primary chamber 600prior to secondary ignition occurring in the secondary chamber 700. Itwill be appreciated that in other embodiments initial ignition occurs inthe secondary chamber 700 and secondary ignition occurs in the primarychamber 600. In such embodiments the piston 100, the protuberance 110,the head 500, and the central recess 510 are configured such that ahigher compression ratio and/or pressure ratio is obtained in thesecondary chamber 700 than in primary chamber 600.

In some embodiments, a housing for valve 400, and or another suitablestructure is positioned within the recess 510 and is configured to varythe volume within the recess 510. In this way, the housing of valve 400is capable of adjusting the compression ratio within the primarycombustion chamber 600 to allow for varying level of performance and/orto accommodate various operating conditions. In some embodiments apiston arrangement similar to that shown in US Published PatentApplication No. 2007/084428, the entire disclosure of which isincorporated herein by reference, is utilized to vary the volume withinthe recess 510. Referring to FIGS. 9 and 10 , an exemplary variablecompression ratio piston 900 houses valve 400, such that piston 900 ismoveable between an open position and a closed position, therebyallowing the variable compression ratio piston 90 to vary the volumewithin the recess 510. In some embodiments, a variable compression ratiopiston is hydraulic (a “Hydraulic Variable Compression-ratio Piston”),while in other embodiments the piston displacement is electro mechanicalhydraulic, piezo-electro mechanical hydraulic, or any other form ofdisplacement now known or hereafter developed. In some embodiments, thevariable compression ratio piston is moved via an electric motor andscrew gear assembly. In some such embodiments, the screw gear assemblyadjusts the variable compression ratio piston up and down as engineRPM's go up and down. In some embodiments, the screw gear assembly isutilized for generally “slower” adjustments of the variable compressionratio piston, in which the variable compression ratio piston ismaintained at a constant location for multiple strokes of the pistonsuch that the variable compression ratio piston is not displaced to adifferent ratio each stroke. In some embodiments, the variablecompression ratio piston is moved up and down via a connecting rod andcam assembly. Some such embodiments allow for much “faster” displacementof the variable compression ratio piston, thereby allowing for thevariable compression ratio piston to be displaced to a different ratioeach stroke. In some such embodiments, the variable compression ratiopiston reciprocates every combustion cycle opposing or otherwisecountering the reciprocating motion of the protuberance(s) of piston 100of the inventive concept. Some such embodiments allow for maximumcombustion in the primary combustion chamber, thereby generating energyto the crank through the valve train while allowing for precombustion.

It will be appreciated that in some embodiments, the variablecompression ratio piston of the inventive concept is a separatestructure from any valve, such that the variable compression ratiopiston's sole function is to vary the volume within recess 510. In someembodiments, the variable compression-ratio piston includes an intakevalve within or as part of the piston, such that the valve is displacedwith the piston. In other embodiments, the valve is separate from thepiston, such that the valve remains in a static location while thepiston is displaced.

Referring to FIGS. 58 through 61 , some embodiments of the variablecompression ratio piston 900 is moveable between first and secondpositions associated with maximum and minimum recess 510 volumes,respectively. In some embodiments, a linkage assembly 910 is utilized tomove the variable compression ratio piston between its first and secondpositions and/or to selectively secure the variable compression ratiopiston in its first position, in its second position, and/or in one ormore intermediate position.

In some embodiments, the present invention includes a control system formonitoring and/or controlling the position of the variable compressionratio piston 900. In some embodiments, the control system utilizes amechanical method and/or an electrical method, such as a reluctor and/orhall effect method, for determining the position of the variablecompression ratio piston. In some embodiments, the control systemincludes first 922 and second 924 sensors for sensing when the variablecompression ratio piston is in its respective first or second position.In some such embodiments, the control system further includes aplurality of intermediate sensors positioned between the first andsecond sensors, each being associated with a respective intermediateposition of the variable compression ratio piston.

In some embodiments, the variable compression ratio piston includes oneor more feature associated with a respective sensor. In someembodiments, a plurality of corresponding features of the variablecompression ratio piston are positioned such that each feature moves inand out of a corresponding sensor's line of sight (and/or otherwisemoves relative to a sensor's sensing area) as the variable compressionratio piston is moved between its first and second position. In thisway, first 912, second 914, and intermediate features are positioned soas to only be sensed by respective first 922, second 924, andintermediate sensors when the variable compression ratio piston 900 isin respective first, second, and intermediate positions, therebyproviding an indication of the current position of the variablecompression ratio piston. In some embodiments, one or more sensor isheld in position by a sensor support member 920.

In some embodiments, a plurality of sensors are spaced-apart along afirst plain and a plurality of corresponding features are spaced apartsuch that each corresponding feature is aligned with a correspondingsensor and positioned on a unique corresponding parallel plain, eachplain being perpendicular to a direction of motion of the variablecompression ratio piston such that only one feature is sensed by asensor at a time. In this way, the control system is capable ofdetermining a current position of the variable compression ratio pistonand/or is capable of moving the variable compression ratio piston to adesired position.

In some embodiments, the present invention further includes one or meansof measuring ambient air pressure and/or for adjusting operation of theengine to accommodate different altitudes, such as an altitude dial. Insome embodiments, the means of adjusting operation of the engineincludes changing air flow and/or fuel flow to accommodate different airqualities and/or mixture requirements.

Still referring to FIGS. 58-61 , some embodiments of the presentinvention include one or more insert 930 for receiving, storing, and/orproviding heat energy. In some embodiments, the insert 930 is made fromone or more material having superior heat transfer properties, such asbrass, copper, titanium, aluminum, or the like. In some embodiments, oneor more insert 930 is at least partially embedded into the head 500, theprotuberance 110, and/or the variable compression ratio piston 900 suchthat the insert 930 is in thermal communication with fluid within therecess 510 immediately before combustion and immediately aftercombustion, thereby resulting in thermal energy from the insert 930moving into the fluid prior to combustion and thermal energy from thefluid moving into the insert 930 after combustion. In this way,regulating the size, shape, location, and material of one or more insert930 allows a user to influence how much thermal energy from a firstcombustion cycle can be stored for promoting one or more futurecombustion cycle. It will be appreciated that in various embodiments,the number and location of insert 930 will vary. In some embodimentsinsert 930 is located in the head and/or piston of embodiments that donot include a variable compression ratio piston. In some embodiments,the insert 930 is a screw inserted into the head, piston and/or variablecompression ratio piston. In some embodiments, the insert 930 is a rivetprojecting through the piston. In some embodiments, the insert 930 is awasher or disc located within the head. It will be a appreciated thatother shapes and mounting mechanisms for insert 930 are included invarious embodiments of the inventive concept.

In some embodiments, the top surface of the protuberance 110 defines aconcave shape. In some such embodiments, a top surface of the recess 510defines a corresponding convex shape. In other embodiments, the topsurface of the protuberance 110 defines a convex shape. In some suchembodiments, a top surface of the recess 510 defines a correspondingconcave shape

In some embodiments a top surface of the main body of the piston 100defines a convex shape while, in other embodiments, the top surface ofthe main body of the piston 100 defines a concave shape. In some suchembodiments, a bottom surface of the head 500 defines a concave shapethat is configured to correspond with a convex shape of the top surfaceof the main body of the piston. In other such embodiments, the bottomsurface of the head 500 defines a convex shape that is configured tocorrespond with a concave shape of the top surface of the main body ofthe piston. It will be appreciated that various embodiments of theinventive concept include all variation permutations of concave andconvex shapes combined with each other along with generally flatsurfaces in combinations with the concave and convex surfaces discussedabove. In still further embodiments, non-curved shapes are utilized. Forexample, in some embodiments the protuberance includes a triangular orpyramidal shaped protrusion that engages an opposing triangular orpyramidal shaped recess. In other embodiments, a square or rectangularshaped nipple and recess is utilized. In some embodiments protuberance110 includes a tapered shape such that width narrows from the top ofprotuberance 110 down to a narrower width toward bottom of protuberance110, at the point in which it intersects with the remainder of piston100. Such a tapered shape helps to reduce or prevent carbon buildupcaused by interference with the cylinder head.

In some embodiments, various edges of the piston and/or head arefilleted, chamfered or otherwise curved, to cause air to move and createa “donut” affect from blow-by of the primary piston and/or to help rolland tumble within the combustion chamber. For example, location 114 inFIG. 9 in some embodiments is filleted. In some embodiments, edge 104 isfilleted. In some embodiments, edge 112 is filleted. In some embodimentsedge 502 of head is filleted. In some embodiments, top surface 102 ofpiston 100, surrounding protuberance 110 is concave in shape, e.g. toform a cup. In other embodiments, surface 102 is convex in shape.

It will be appreciated that the dimensions and shape of variousprotuberances 110 and corresponding central recesses 510 will vary inembodiments of the invention to provide the desired compression and/orpressure ratios and performance. In some embodiments in which multipleprotuberances are utilized, the sizes and shapes vary to createdifferent combustion chambers, e.g. primary, secondary, tertiary, etc.In such embodiments, the volumes will vary to provide for differentcompression and/or pressure ratios. In some embodiments, multipleprotuberances will have different dimensions, but will have equalvolumes to provide for equivalent compression and/or pressure ratios. Insome embodiments, the central protuberance creates a primary combustionchamber, while other protuberances surrounding the central protuberancecreating secondary (or tertiary, etc.) combustion chambers, and with thereminder of the combustion chamber (e.g. chamber 700) being a tertiary(or subsequent) combustion chamber. In other embodiments, one or moreprotuberances surrounding the central protuberance will be the primarycombustion chamber. It will further be appreciated that the bore andstroke, and other engine design parameters will vary to optimize, reduceor increase the design for different types of fuel.

Some embodiments of the inventive concept include an opposed pistondesign similar to those discussed above. In some such embodiments thereis a single primary piston combined, in some embodiments, with thevariable compression ratio piston discussed above that mates with theprimary piston all within a single cylinder. In other embodiments,opposing pistons operate within separate opposing cylinders. In somesuch embodiments, variable compression ratio pistons are also utilized.

Embodiments of the inventive concept produce on demand flame and/orpressure propagation by creating compression ignition in the primarycombustion chamber and allowing the combustion to propagate to thesecondary chamber as the piston moves away from the head, therebyincreasing the volume.

It will be appreciated that embodiments of the multi-phase andmultiphasic dynamic compression ignition combustion engines disclosedherein will include varying numbers of cylinders (e.g. 1, 2, 4, 6, 8,etc.), and varying cylinder displacements. In some embodiments of theinstant invention, a lower number of cylinders is utilized (e.g. 2cylinders) to provide the same total engine displacement as what istypically found in higher number of cylinder engines (e.g. 8 cylinders).Because the inventive concept allows for complete compression ignitioncombustion and/or on demand flame and/or pressure propagation, the boresize of the cylinders can be scaled up and down as desired without anyincrease in emissions or decrease in efficiencies. In some embodiments,an opposed two cylinder structure is utilized to design a higherdisplacement (e.g. 4.0 liters, etc.) engine. Such a structure results insmaller overall size of the engine, as well as material and labor savingin manufacturing.

In some embodiments of the inventive concept a heat storage medium isincluded on the top of the piston, such as on top of the protuberance ofthe inventive concept, and/or on the cylinder head, such as near thecenter of the top of the cylinder. In some embodiments, the heat storagemedium is designed to retain heat and become hotter than the walls ofthe cylinder or piston. In some such embodiments, the increased heat ofthe storage medium then dissipates into the compressed charge to assistwith auto-ignition near the storage medium. In some embodiments, theheat storage medium is a relatively small piece of metal or othermaterial having suitable thermodynamic properties to store and releaseheat to aid in auto-ignition as described. In some embodiments, the heatstorage medium is a coating that is applied to a surface of the pistonand/or the head.

In some embodiments, a ceramic coating, an anodized coating, or othersuitable heat resistant coating or surface feature now known orhereafter discovered, is added to the cylinder head and/or pistonsurface(s) to improve heat resistance and prevent/minimize torchingdamage to the aluminum or other material of which the piston/head areconstructed.

In some embodiments pre-heaters are included on or in association withan intake manifold to heat up the air/fuel and/or water entering theengine to aid with startup and performance.

In some embodiments (see for example FIGS. 20 through 22 ) an engine ofthe inventive concept includes offset intake and exhaust valvespositioned around the central valve associated with the centralprotuberance of the piston and its associated recess. In some suchembodiments, the exhaust valves are located on the right and left sidesof the engine, and the intake valves are in-line with the crank. In somesuch embodiments, the exhaust ports extend up from the exhaust valvesand out toward the right or left of the respective exhaust valves. Theoffset location of the exhaust valves to the intake valves allows forbalanced temperature within the combustion chamber. The location of thevalves in some embodiments allow for even greater balance and for heatfrom combustion to be pulled away from the center of the cylinder andthe intake. In some embodiments, the heat pulled away is used to preheatthe intake. In other embodiments, the heat is not used to preheatintake. Nevertheless, it will be appreciated that in other embodimentsutilizing the offset valve design, the intake and exhaust valvelocations are reversed. In some embodiments, the central valve functionsas both an intake and an exhaust valve. In some embodiments, all valvelocations are capable of being either intake, exhaust and/or both intakeand exhausted depending upon the desired flow characteristics desiredwithin the cylinder. In various embodiments, the order, duration, and/ortiming of each valve opening and closing varies and is designed toachieve desired flow characteristics within the cylinder. It will beappreciated that the offset valve design of the inventive concept willbe utilized in various embodiments with compression ignition as well asconventional ignition engines.

Referring to FIGS. 18A, 18B and 18C, some embodiments of the inventiveconcept include a multi-stage direct injector. The injector includes a“stepped” injector pin that is pulled up from its seat a small amount toopen a first stage that allows a first lowest amount of flow. Referringto FIG. 18A, the injector pin 1000 is in a seated position withinhousing 1200, in which no fluid flow will occur. FIG. 18B shows theinjector pin 1000 after it has moved from the seated position to open afirst stage of fluid ports 1100. As the injector is pulled further up,it opens successively larger holes through its stepped design to opensecond, third, fourth, fifth, etc. stages, increasing the amount of flowprogressively at each stage. FIG. 18C shows the injector pin 1000 afterit has moved from the first stage of FIG. 18B to a second stage in whichadditional fluid ports 1100 have been open. As is shown in FIG. 18C, athird stage of fluid ports 1100 remain closed by injector pin 1000. Insome embodiments, O-rings are included along each stage of the injectorto improve scaling. In the embodiments shown in FIGS. 18A, B and C, asingle fuel/fluid line is shown feeding the injector. In otherembodiments, each stage of the injector is fed by a separate fuel line.In this manner, the injector is utilized in some embodiments to feeddifferent fuels types or other fluids through each stage. For example,in some embodiments (such as in a drag car), a first stage injectsalcohol, a second stage injects a first stage of nitrous, and thirdstage injects a second stage of nitrous. In some embodiments, theinjector of the inventive concept is utilized in connection with acarbureted engine, while in other embodiments it is utilized as part ofa fuel injection system. In some embodiments, the injector of theinventive concept is utilized on a turbine fan. In other embodiments,the injector is utilized as a plastics injector, e.g. for multiple-stageinjection molding of plastics. In still other embodiments, the injectoris utilized as an oil injector. In various embodiments, the presentinvention includes one or more injector, such as one or more direct fuelinjector, extending through a wall of the head into one or more chamber.

Referring to FIGS. 19A, B, and C, various embodiments of engines of theinventive concept are shown including a butterfly valve 465 designed totrap selectively heat and/or exhaust gases within the combustion chamberto aid in compression ignition. FIG. 19A shows an embodiment of a twocycle engine of the inventive concept in which the piston functions asthe exhaust and intake valves selectively block intake 450 and exhaustoutlet 460, and further including a butterfly valve 465 within theexhaust outlet 460 to trap selectively heat and exhaust gas inside thecombustion chamber to aid in compression ignition. Intake valve 400 islocated within recess 510 of the cylinder head to reduce and/oreliminate trap volume within that portion of the combustion chamber. Insome embodiments of the engine shown in FIG. 19A, in which a singleexhaust port is present, the butterfly valve 465 is never 100% closed.Instead, the valve is partially closed to trap part of the exhaust andpreheat the intake. In other embodiments, in which multiple exhaustports, or lines, are present, the butterfly valve 465 is capable ofclosing a portion of the exhaust 100% to provide the desired flowrestriction and/or preheating affect. FIG. 19B shows the butterfly valve465 in an embodiment in which the piston functions as the exhaust valveand in which a separate intake valve 450 is utilized along with valve400. FIG. 19C shows the butterfly valve 465 in an embodiment of a two orfour cycle engine in which the exhaust valve is located within the headalong with intake valves 450 and 400. In will be appreciated that inother embodiments the butterfly valve 465 is utilized in engines thatonly include a single combustion chamber, compared to the primary andsecondary (tertiary and so forth) chambers shown in FIGS. 19A through19C. Furthermore, although not shown in FIGS. 19B and 19C, it will beappreciated that the variable compression ratio piston 900 is includedin various embodiments of the inventive concepts of FIGS. 19B and 19C.Similarly, various embodiments of the inventive concept of FIG. 19A areutilized without the variable compression ratio piston 900 showntherein.

Various embodiments of the instant inventive concept described hereinare included and/or utilize multiphasic dynamic compression ignitioncombustion in a two cylinder supercharged engine of the type discussedin PCT/US2014/64866, the entire disclosure of which is incorporatedherein by reference. It is understood that various embodiments of theinventive concept disclosed herein include single cylinder, twocylinder, and additional cylinder (e.g. 3, 4, 5, 6, 7, 8, etc.cylinders) structures, and also include structures with and without anytype of intake boost (e.g. superchargers and/or turbo chargers)(including, but not limited to the structures disclosed inPCT/US2014/64866).

Referring to FIGS. 20 and 21 , an exemplary embodiment of the inventiveconcept is shown as a three cylinder, Siamese cylinder, engine whichincludes three pistons 100 within cylinders 300 (and 301 and 302), thateach includes a generally central protuberance 110 protruding from thetop of the main body of the piston. The cylinder head 500 includes agenerally central recess 510 (and 511 and 512) within each cylinder thatis configured to matingly receive the protuberance 110 of the piston foreach cylinder. The central protuberance 110 of the piston is adapted tobe slidingly received in the central recess 510 (and 511 and 512) of thehead. As the piston moves up toward top dead center, the centralprotuberance 110 of the piston slides into the central recess 510 (and511 and 512) of the head, creating a primary combustion chamber, andsecondary combustion chamber. In some embodiments, the respectivevolumes of primary combustion chamber and secondary combustion chamberare designed such that the compression ratio and/or pressure ratio ofthe primary combustion chamber is higher than that of the secondarycombustion chamber (in other embodiments, the reverse is true). In thatmanner, auto-ignition is obtained in the primary combustion chambereither before, at, or after the piston reaches top dead center, withoutresulting in auto-ignition within the secondary combustion chamber. Asthe piston moves down from top dead center and protuberance 110 movesout of recess 510 (and 511 and 512) of the head, the pressure created bythe combustion within the primary combustion chamber is allowed toexpand into the secondary combustion chamber, initiation combustions,ignition and/or combustion ignition within the secondary combustionchamber. In some embodiments, auto-ignition is initiated from pressurepropagation through blow-by of primary to secondary combustionschambers, or vice versa.

With respect to each of the cylinders, a central intake valve 400 (and401 and 402) is located within the recess 510 (and 511 and 512) of thecylinder head to reduce and/or eliminate trap volume within thecombustion chamber, and to ensure a homogenous air/fuel/EGR mix withinthe entire combustion chamber (primary and secondary chambers). In theembodiment shown, additional intake valves 410 (and 420 and 430) and 412(and 422 and 432) and exhaust valves 415 (and 425 and 435) and 417 (and427 and 437) are located in the secondary combustion chamber areas. Inthe embodiment shown, all intake valves (400, 401, 402, 410, 412, 420,422, 430 and 432) are positioned along a centerline of the engine block.In this manner intake valves 412, 420, 422 and 430 are located in closeproximity and adjacent to the cylinder walls of adjoining pistons, whichare locations in which hot spots are created. The location of the valvesand air flow created through the valves allows heat to soak betweenadjoining cylinders and away from the hot spot locations. The improvedbalance of heat throughout the engine allows for greater control and useof compression ignition. It will be appreciated that the balancing ofheat of the inventive concept is utilized in combination with singlecylinder and other multiple cylinder embodiments (e.g. 2 cylinder, 4cylinder, etc.).

Referring to FIG. 21 , a dual overhead cam arrangement is shown. Centralintake valves 400, 401 and 402 are controlled by overhead camshaft 1600.Secondary combustion chamber intake valves 410, 412, 420, 422, 430 and432, as well as exhaust valves 417, 417, 425, 425, 435 and 437 are allcontrolled by overhead cam shaft 1700 located directly above overheadcam shaft 1600. Rocker arms 715 and 710 (rocker arms associated withcylinders 301 and 302 not shown) extend from cam shaft 1700 to exhaustvalves 415 and 417, respectively. In other embodiments, a single cam isutilized to control all valves. In still other embodiments, three ormore cams are utilized. In some three cam embodiments, a central camshaft controls the central intake valves, while a cam on each side ofthe engine controls the respective valves on that side of the engine. Instill other embodiments, mechanical, electronic and/or hydrauliccontrollers and/or a combination thereof or utilized to control thevarious valves. It will be appreciated that in various embodiments, someor all exhaust valves shown herein are utilized as intake valves, andsome or all intake valves shown herein are utilized as exhaust valves.In addition, in some embodiments, the same valve functions as both anexhaust and intake valve, depending upon the desired engine performance.Although a duel overhead cam is shown in FIG. 21 , in other embodiments,a single cam is utilized to control both the exhaust and the intake. Inother embodiments, three or more cams are utilized. Instill otherembodiments, other mechanisms for valve actuation are utilized. In someembodiments, the intake valves are electronically actuated, while theexhaust valves are mechanically controlled by a cam. Although not shownin FIG. 21 , it will be appreciated that in some embodiments a variablecompression ratio piston is utilized in combination with the structureshown in FIG. 21 .

In some embodiments, the multiple intake valves shown within a singlecylinder (e.g. in FIG. 20 ) are controlled to open in a staggeredpattern to help control roll and tumble of the air/fuel/EGR mixturewithin the combustion chamber. In some embodiments in which the intakevalves are controlled by a cam, the valves opening is staggered from1-20 degrees from one another. In some embodiments, one intake valve isopened at a time in a staggered pattern. In other embodiments, multiplevalves are open at the same time with another valve opened in astaggered pattern. It will be appreciated that the pattern will vary indifferent embodiments depending upon the desired sweeping motion withinthe combustion chamber as well as the physical shape, size and design ofthe components.

Referring to FIG. 21 , in the embodiment shown, the design of piston100, with the protuberance 110 located at the center of piston 100,allows the wrist-pin 210 to attach rod 200 to the piston at a locationof increased thickness of the piston (due to the protuberance). Thisincreases strength at a location that otherwise is under increasedstress. In addition, the relatively high connection on the piston allowsfor greater control of the piston and decreased piston slap as thepiston moves up and down within the cylinder.

In some embodiments of the engine shown in FIGS. 20 and 21 , intake andexhaust manifolds are designed such that the at least a portion of theexhaust lines are in physical contact, or at least in close proximity tothe intake lines. In this manner the exhaust lines are utilized topreheat the intake. In some embodiments, a butterfly valve, similar tothat shown in FIGS. 19A, B and C, is utilized to divert exhaust gas froma portion of the exhaust manifold that is in contact/proximity to theexhaust lines to a portion of the exhaust manifold that is positionedaway from the intake lines. In this manner, the preheating can beselectively engaged and disengaged utilizing the valve. In someembodiments, the valve is located at a “T” in the manifold, and theexhaust lines come out from the ports generally in parallel to theintake lines, with the “T” diverting the exhaust down and away from theintake lines, or when not selectively diverted, allowing the exhaustgases to flow through the portion of the manifold that continues inparallel to the intake lines (and in contact or close proximity to theintake lines). In some embodiments there is a separate intake lineentering from each side of the engine, along with exhaust lines on eachside of the engine, to provide balanced heat transfer. In someembodiments, the intake and exhaust line on each side of the engine areside-by-side (in physical contact or close proximity to one another) andbend upward toward the top of the engine. The intake lines meet eachother and connect together at the top of the engine and in someembodiments a fuel injector is located at the top of the intake. In someembodiments, the exhaust lines also meet each other and connect togetherand flow outward in a single exhaust pipe near the point ofintersection. In other embodiments, each exhaust line continues over thetop of the engine and down the opposing side from which it originatedand then outward from the engine. In some embodiments, the intake andexhaust manifold is a single molded or cast piece that bolts over theengine head. In some embodiments in which the intake lines come togetherat the top of the engine

Referring to FIG. 22 , a top plan view of another embodiment of a threecylinder Siamese cylinder engine that includes multiple protuberances ofthe inventive concept. In addition to protuberance 110 (which in FIG. 22engages with recesses 510 a, 511 a, and 512 a), other protuberances arelocated around the top of the piston surrounding protuberance 110 andengage with recesses 510 b, c, d, and e, 511 b, c, d, and e, and 512 b,c, d and e. It will be appreciated that the numbers, sizes, shapes andlocations of the protuberances will vary in different embodiments. Insome embodiments, each protuberance has a different volume to provide adifferent compression result (e.g. creating primary, secondary,tertiary, etc. combustion chambers). In other embodiments, the volume ofeach protuberance is equal to provide the same compression within eachrecess.

Referring to FIGS. 23-57 , some embodiments of the present inventioninclude one or more valve positioned in an engine block, such as in afat head configuration. In some embodiments, the valves are placed inthe engine block beside the piston with a recess in the cylinder headcreating a corridor connecting the valves to the combustion chamber. Insome embodiments, the valves are located to one side of the piston,and/or only one intake and one exhaust valve are utilized for eachpiston. In the embodiment shown in FIGS. 23-25 , two exhaust and twointake valves are utilized with each cylinder. In some embodiments, oneintake and one exhaust valve are located on each side of the piston. Inother embodiments, two intake valves are located on one side and twoexhaust valves are located on the other side. Still in otherembodiments, a single valve is intake and three valves are exhaust. Infurther embodiments a single valve is exhaust and 3 valves are intake.In still other embodiments, more than 2 valves are located on each sideof the piston, with various arrangements of intake and outs. In stillfurther embodiments, some valves function as both intake and exhaust.

In the embodiment shown in FIGS. 23-25 , a central intake valve (or insome embodiments an exhaust valve, or in some embodiments andcombination exhaust/intake valve) is located within the recess thatreceives the nipple portion of the piston. In some embodiments, thecentral valve helps to reduce and/or eliminate trap volume. In someembodiments, the central valve is not needed to reduce trap volume asthe control of the multiple valves to the sides of the piston create acyclonic action within the combustion chamber that helps to evacuate therecess. In some embodiments the side valves are located on only one sideof the piston. In some such embodiments, only a single intake and singleexhaust valve is utilized to the side of the piston along with thecentral valve within the recess.

In some embodiments, engine blocks include one or more group of sidevalves positioned on one or more side of a piston. In some embodiments acenter valve of a group of three valves is an exhaust valve and thevalve on either side of the exhaust valve is an intake valve, or viceversa. In other embodiments, a center valve of a group of three valvesperforms the same function (intake or exhaust) as one or more end valveof the group. In some embodiments the valves are positioned along an arc(FIG. 26, 27 ) or other curve. In some embodiments the valves arepositioned along a straight line, such as a straight line extending in atangential (FIG. 36 ), slanted (FIG. 38 ), or radial (FIG. 42 )direction.

In some embodiments, a center valve of a first group of valves is anexhaust valve and a corresponding center valve of a second group ofvalves is an intake valve. In some embodiments, two exhaust valves andone intake valve are located adjacent to a first side of a piston andone exhaust valve and two intake valves are located adjacent to a secondside of the piston such that half of the valves are exhaust valves andthe other half of the valves are intake valves. In yet otherembodiments, each valve located adjacent to the first side of the pistonis an exhaust valve and each valve located adjacent to the second sideof the piston is an intake valve. It will be appreciated that otherembodiments include different numbers and/or configurations of valvesand/or varying sizes of valves (e.g. different sizes than shown in thevarious drawings and/or at least one valve within a set of valves beingdifferent in size from at least one other valve).

In some embodiments, a corresponding head includes one or more recessarea for connecting one or more valve or set of valves to one or morecombustion chamber of the engine block. In some embodiments, one or morerecess defines one or more corridor. In some embodiments, first andsecond corridors connect respective first and second groups of valves torespective first and second combustion chambers. In some embodiments,first and second corridors connect respective first and second valves ofa first group of valves to respective first and second combustionchambers. In some embodiments, a first corridor connects a first valveto a first combustion chamber and a second corridor connects the firstcombustion chamber to a second valve and/or to a second combustionchamber.

Referring to FIGS. 42-57 , some embodiments include two or more valvespositioned along a straight line extending in a radial direction. Insome such embodiments, a distal valve defining a first diameter islarger than a second diameter of a proximal valve. It will beappreciated that other configurations include valves positioned alongdifferent lines (or not along lines at all) and/or having differentplacement and/or size configurations. In some embodiments, side valvesarc located on the front/flywheel side of the engine block. In someembodiments, the side valves are located on the rear side of the engineblock.

In some embodiments, a distal valve is an intake valve and a proximalvalve is an exhaust valve. In some embodiments, the intake valve definesa first diameter that is larger than a second diameter of the exhaustvalve. In other embodiments the intake valve is the same size as theexhaust valve. In still other embodiments, the intake valve is smallerthan the exhaust valve. In some embodiments, the location of the valvesand air flow created through the valves allows and/or facilitates heatto soak away from one or more hot spot location of the engine. In someembodiments, improved balance of heat throughout the cylinder allows forand/or facilitates greater control and use of compression ignition.

In some embodiments, the piston includes a central protuberance/nipplethat is associated with a central recess in the head. In someembodiments a valve is not included within the central recess. In someembodiments, the head, block, valve, and pistons are configured so as toprovide sufficient air flow to eliminate and/or control trap volumewithin the entire combustion chamber. In some such embodiments, a valvewithin the central recess valve is not required to eliminate and/orcontrol trap volume. In some embodiments, a central valve is includedwithin the central recess in some embodiments to further control trapvolume.

The valves shown and described in the above-embodiments of the inventiveconcept are controlled in various embodiments by mechanical, electrical,mechanical-electrical, hydraulic, combinations thereof, and/or othermechanisms for actuation now known or hereafter discovered. Although camand rocker arm assemblies are shown in some embodiments above, it willbe appreciated that in other embodiments, other valve actuationmechanisms will be utilized in connection with the same or similarfeatures of the inventive concept therein described. In variousembodiments, intake and exhaust valves are actuated in or out ofsequence, depending upon design and performance desired.

Although not shown and described herein, it will be appreciated thatvarious embodiments of the Siamese cylinder inventive concept areemployed with the various features, combinations and subcombinations ofthe other systems and methods of compression ignition disclosed herein.

In the foregoing description, certain terms have been used for brevity,clearness and understanding; but no unnecessary limitations are to beimplied therefrom beyond the requirements of the prior art, because suchterms are used for descriptive purposes and are intended to be broadlyconstrued. Moreover, the description and illustration of the inventionsis by way of example, and the scope of the inventions is not limited tothe exact details shown or described.

Although the foregoing detailed description of the present invention hasbeen described by reference to an exemplary embodiment, and the bestmode contemplated for carrying out the present invention has been shownand described, it will be understood that certain changes, modificationor variations may be made in embodying the above invention, and in theconstruction thereof, other than those specifically set forth herein,may be achieved by those skilled in the art without departing from thespirit and scope of the invention, and that such changes, modificationor variations are to be considered as being within the overall scope ofthe present invention. Therefore, it is contemplated to cover thepresent invention and any and all changes, modifications, variations, orequivalents that fall within the true spirit and scope of the underlyingprinciples disclosed and claimed herein. Consequently, the scope of thepresent invention is intended to be limited only by the attached claims,all matter contained in the above description and shown in theaccompanying drawings shall be interpreted as illustrative and not in alimiting sense.

Having now described the features, discoveries and principles of theinvention, the manner in which the invention is constructed and used,the characteristics of the construction, and advantageous, new anduseful results obtained; the new and useful structures, devices,elements, arrangements, parts and combinations, are set forth in theappended claims.

It is also to be understood that the following claims are intended tocover all of the generic and specific features of the invention hereindescribed, and all statements of the scope of the invention which, as amatter of language, might be said to fall therebetween.

What is claimed is:
 1. An internal combustion engine comprising: acylinder; a first piston located within said cylinder, said first pistonincluding a protuberance and being configured to move between atop-dead-center (“TDC”) and a bottom-dead-center (“BDC”) configuration,thereby defining a stroke of the first piston; and a cylinder headenclosing said first piston within said cylinder, said cylinder headincluding a recess associated with said protuberance, wherein saidcylinder, cylinder head, and recess define a combustion chamber having aprimary chamber and a secondary chamber, a bottom surface of saidprimary chamber being defined by a top surface of said protuberance whensaid protuberance is received by said recess, wherein the engineperforms a dual-ignition combustion process, a first ignition processoccurring in the primary chamber and a second ignition process occurringin the secondary chamber as the first piston is moving away from TDC,and wherein the second ignition process comprises expansion of fluidinto the secondary chamber from the primary chamber.
 2. The engine asclaimed in claim 1, further comprising a spark plug extending into theprimary chamber, the spark plug being configured to selectively initiatethe first ignition process.
 3. The engine as claimed in claim 2, furthercomprising a glow plug extending into the primary chamber, the glow plugbeing configured to selectively initiate the first ignition process. 4.The engine as claimed in claim 1, L further comprising a glow plugextending into the primary chamber, the glow plug being configured toselectively initiate the first ignition process.
 5. The engine asclaimed in claim 1, further comprising a second piston, wherein theprimary chamber defines a first volume when the first piston is at TDC,wherein the second piston is a variable compression ratio pistonassociated with the primary chamber, and wherein the second piston ismoveable between a first position and a second position, the first andsecond positions of the second piston being associated with maximum andminimum values of the first volume, respectively.
 6. The engine asclaimed in claim 5 wherein the first ignition process is a compressionignition process.
 7. The engine as claimed in claim 6, wherein thesecond ignition process occurs after said first piston has moved awayfrom TDC.
 8. The engine as claimed in claim 5, further comprising alinkage assembly for moving the second piston between its first andsecond positions, thereby adjusting compression ratios associated withthe primary chamber.
 9. The engine as claimed in claim 8, wherein saidlinkage assembly is configured to selectively secure said second pistonat its first position, at its second position, or at one of a pluralityof intermediate positions.
 10. The engine as claimed in claim 8, furthercomprising a control system having first and second sensors associatedwith respective first and second features of the second piston such thatthe first and second sensors are aligned with respective first andsecond features when the second piston is in respective first and secondpositions.
 11. The engine as claimed in claim 5, further comprising acontrol system having first and second sensors associated withrespective first and second features of the second piston such that thefirst and second sensors are aligned with respective first and secondfeatures when the second piston is in respective first and secondpositions.
 12. The engine as claimed in claim 11, wherein said controlsystem further comprises an intermediate sensor associated with anintermediate feature of the second piston such that the intermediatesensor is aligned with the intermediate feature when the second pistonis in a respective intermediate position.
 13. The engine as claimed inclaim 11, further comprising an insert at least partially embedded in afirst component, wherein the first component is one of the first piston,the head, and the second piston, wherein the first component is formedfrom a first material, wherein the insert is formed from a secondmaterial having heat transfer properties that are different from heattransfer properties of the first material, and wherein the insert ispositioned and configured so as to be in thermal communication with theprimary chamber.
 14. The engine as claimed in claim 1, furthercomprising an insert at least partially embedded in a first component,wherein the first component is one of the first piston, the head, andthe second piston, wherein the first component is formed from a firstmaterial, wherein the insert is formed from a second material havingheat transfer properties that are different from heat transferproperties of the first material, and wherein the insert is positionedand configured so as to be in thermal communication with the primarychamber.
 15. The engine as claimed in claim 14, further comprising aplurality of inserts, each insert being at least partially embedded inone of the first piston, the head, and the second piston.
 16. Aninternal combustion engine comprising: a cylinder; a first pistonlocated within said cylinder, said first piston including a protuberanceand being configured to move between a top-dead-center (“TDC”) and abottom-dead-center (“BDC”) configuration, thereby defining a stroke ofthe first piston; a cylinder head enclosing said first piston withinsaid cylinder, said cylinder head including a recess associated withsaid protuberance; and a second piston, wherein said cylinder, cylinderhead, and recess define a combustion chamber having a primary chamberand a secondary chamber, wherein the primary chamber defines a firstvolume when the first piston is at TDC, wherein the second piston is avariable compression ratio piston associated with the primary chamber,wherein the second piston is moveable between a first position and asecond position, the first and second positions of the second pistonbeing associated with maximum and minimum values of the first volume,respectively, wherein a bottom surface of said second piston defines atleast part of a top surface of said primary chamber, and wherein saidsecond piston is displaced from said secondary chamber.
 17. The engineas claimed in claim 16 further comprising a linkage assembly for movingthe second piston between its first and second positions, therebyadjusting compression ratios associated with the primary chamber. 18.The engine as claimed in claim 17, further comprising a control systemhaving first and second sensors associated with respective first andsecond features of the second piston such that the first and secondsensors are aligned with respective first and second features when thesecond piston is in respective first and second positions.
 19. Aninternal combustion engine comprising: a cylinder; a first pistonlocated within said cylinder, said first piston being configured to movebetween a top-dead-center (“TDC”) and a bottom-dead-center (“BDC”)configuration, thereby defining a stroke of the first piston; a cylinderhead enclosing said first piston within said cylinder, thereby defininga combustion chamber, a spark plug extending into said combustionchamber the spark plug being configured to selectively initiate a firstignition process; and a glow plug extending into said combustionchamber, the glow plug being configured to selectively initiate thefirst ignition process.